Containers for packaging stacks of semiconductor components are formed by tubes in which the stacks are placed for packaging and ultimately for use as a magazine for feeding the components to automatic electronic assembly equipment.
Such a container has been made in the form of an extruded transparent plastic tube having a profile preventing the components from rotating in the tube while permitting them to slide longitudinally for feeding. Transparency permits visual inspection of the components.
Such components can be destroyed by small static electric charges. Protection against such charges can be provided by coating the transparent, and therefore electrically non-conductive, plastic with antistatic coating material.
Ambient electromagnetic interference (EMI) is currently increasing to levels also capable of charging and destroying such sensitive components. EMI shielding can be provided by making such a container from an electrically conductive plastic extruded into the tubular form, but to make a plastic adequately conductive, it must be loaded with a conductive material so that the plastic is no longer transparent.
Polyvinylchloride (PVC) is one example of a suitable extrudable plastic from which tubular forms can be produced, whether the plastic is transparent and electrically non-conductive or opaque and electrically conductive because loaded with electrically conductive material, as exemplified by carbon black or graphite or metal fibers. It is possible to coextrude PVC by the simultaneous extrusion of several melt streams to make a product that has different characteristics in various areas of its cross section, the coextruded product being integral throughout.